Plastic filter leaf with separator channels

ABSTRACT

A filter leaf assembly is disclosed which may be used in either a horizontal rotary leaf filter or a vertical filter. The filter leaf assembly comprises a leaf member of a synthetic plastic material with both faces of the leaf member being provided with a regular pattern of closely spaced cylindrical projections. The projections are integral with the leaf member. Filter media are mounted on both faces of the leaf member over these cylindrical projections. The leaf member may be circular and mounted upon a hub having passages therein communicating with both sides of the leaf member. The leaf member may be rectangular and a hose connection attached along one edge thereof to communicate with both faces of the leaf member.

United States Patent Krynski et al.

[ Mar. 14, 1972 3,501,010 3/1970 Caitchelletal ..210/486X Primary Examiner-Samih N. Zaharna Assistant Examiner-Frederick F. Calvetti Attorney-Smythe & Moore [5 7] ABSTRACT A filter leaf assembly is disclosed which may be used in either a horizontal rotary leaf filter or a vertical filter. The filter leaf assembly comprises a leaf member of a synthetic plastic material with both faces of the leaf member being provided with a regular pattern of closely spaced cylindrical projections. The projections are integral with the leaf member. Filter media are mounted on both faces of the leaf member over these cylindrical projections. The leaf member may be circular and mounted upon a hub having passages therein communicating with both sides of the leaf member. The leaf member may be rectangular and a hose connection attached along one edge thereof to communicate with both faces of the leaf member.

3 Claims, 10 Drawing Figures PATENTEDMAR 14 I972 33, 5

sum 3 [1F 3 FlG.-8

ATTORNEYS PLASTIC FILTER LEAF WITH SEPARATOR CHANNELS One form of a pressure filter device comprises a succession of filter plates which may be arranged horizontally or vertically. The faces of the filter plates are provided with grooves or other passages and the faces are then covered with suitable filter media. The liquid to be filtered is introduced upon the filter media with the filtrate passing through the filter media into the grooves on the filter plate surfaces. The filter cake remaining on the filter media is then removed. One of the problems in connection with such pressure filter devices is to provide on the filter plates uniform supporting surfaces for the filter media while at the same time providing as large a filter area as possible. It is also necessary that the supporting surfaces have relatively simple and uncomplicated passages therebetween so as to permit a free flow of the filtrate.

One of the objects of the present invention is to provide an improved filter leaf assembly for a pressure filter device.

Another of the objects of the present invention is to provide a filter leaf member having on both faces thereof uniform sup porting surfaces for filter media.

Another of the objects of the present invention is to provide a filter leaf member of a synthetic plastic material having integral projections on both faces thereof to form uniform supporting surfaces for filter media.

According to one aspect of the present invention, a filter leaf assembly may comprise a relatively thin leaf member of a synthetic plastic material having sufficient thickness to be structurally self-supporting and having opposed faces. Each of the leaf member faces has a plurality of cylindrical projections thereon which are relatively closely spaced in a regular pattern. The cylindrical projections are of a uniform height and are integral with the leaf member. Filter media are positioned on both sides of the leaf faces and supported on the ends of these cylindrical projections. The leaf member may be circular for use in a horizontal pressure filter device or may be rectangular with a hose connection at an edge thereof for use in a vertical pressure filter device.

Other objects, advantages, and features of the present invention will be apparent from the accompanying description and drawings, which are merely exemplary.

In the drawings:

FIG. 1 is a plan view of a circular filter leaf assembly according to the present invention with a portion of the filter media cut away;

FIG. 2 is an end view of the filter leaf assembly of FIG. 1;

FIG. 3 is an elevational view of the hub for the filter leaf assembly for FIG. 1 with the lower portion of the hub being shown in section;

FIG. 4 is an end view ofthe flanged end ofthe hub of FIG. 3;

FIG. 5 is a longitudinal sectional view of the compressor ring used in the assembly of the filter leaf member upon the hub;

FIG. 6 is a sectional view taken along the line 6--6 of FIG. 1 and in enlarged scale;

FIG. 7 is a sectional view taken along the lines 77 of FIG.

FIG. 8 is a plan view similar to that of FIG. 1 ofa rectangular filter leaf member for a vertical filter device;

FIG. 9 is an end view of the filter leaf member of FIG. 8; and

FIG. 10 is a sectional view taken along the line l0-l0 of FIG. 8 and in enlarged scale.

Proceeding next to the drawings wherein like reference symbols indicate the same parts throughout the various views, a specific embodiment and modification of the present invention will be described in detail.

A filter leaf assembly according to the present invention is indicated generally at 10 in FIGS. 1 and 2. The assembly comprises a relatively thin leaf member 11, as shown in FIG. 6, of a plastic material such as polypropylene. In one form, the plastic may be of foamed plastic. The member has a sufficient thickness to be structurally self-supporting and has opposed faces 12 and 13. Each face is provided with a plurality of cylindrical projections 14, shown in FIG. 7, which are relatively closely spaced in a regular pattern. These cylindrical members are of a uniform height with their ends 15 presenting a supporting surface for a filter media 16. The cylindrical projections are formed integrally with the member 11 as also shown in FIG. 7. The projections 14 are arranged in a regular pattern as shown in FIG. 1 and present a substantially waffle-iron effeet.

The filter leaf member 10 is circular and is provided with a central opening 17 in which is mounted a hub 18. The circular leaf member is intended for a horizontal rotary leaf filter device.

At the peripheral edge of each face 12 and 13, there is provided a rib 19 with the radial face of the rib being of the same height as the cylindrical projections 14. The uniform heights of the rib l9 and the projections 14, together with the close but regular spacing of the projections, provide a uniform supporting surface for the filter media 16.

An annular groove 20 is formed in the outer peripheral edge of the leaf member 11.

The filter media 16 may be a screen and/or cloth which covers both radial faces of the leaf member as shown in FIG. 6. The outer edges of the filter media may be held within the peripheral groove 20 by suitable caulking 21. A molded leaf binding 22 having a substantially U-shaped cross section is positioned about the peripheral edge of the leaf member 11 to retain the caulking and the peripheral edges of the filter media in position. The binding may be in two sections as shown in FIG. 1 and clamped together at their ends as at 23.

The hub 18 is substantially cylindrical and has an external flange 24 at an end thereof. The peripheral surface of the hub is provided with a pair of annular grooves 25 which communicate with the interior of the hub through openings 26. Axial grooves 27 may be formed in the inner face of hub 18 and communicate with the openings 26.

The leaf member 11 with filter media 16 on both sides thereof is positioned over the hub against the flange 24. The leaf member is held in this position by means of a compression ring 28 secured by bolt 29 which passes through openings in the leaf member 11 and the flange 24. The compression ring 28 is provided with an annular groove in which is seated a Neoprene O-ring 30. It can be seen that when the leaf member is mounted upon the hub, the hub grooves 25 communicate with both faces 12 and 13 of the leaf member.

Proceeding next to FIGS. 8-10, there is indicated generally at 31, a rectangular filter leaf assembly which is particularly adapted for a vertical filter device. The construction of the filter leaf assembly 31 is substantially the same as that of the assembly 10 described above. However, instead of having an opening in the center of the leaf member, a hose or conduit connection 32 is attached to an edge of the leaf member. The connection comprises a substantially channel-shaped member 33 provided with a longitudinal groove 34 which communicates with both faces of the leaf member as may be seen in FIG. 10. The element 33 is secured to the leaf member by a plurality of rivets or bolts 35. A hose or conduit connection 36 having a bore 37 is then secured to the element 33 to communicate with a bore 38 therein.

The regularly spaced cylindrical projections similarly function to provide a uniform supporting surface for the filter media positioned on both faces of the leaf member. The leaf member is also formed of a synthetic plastic material such as polypropylene and the cylindrical projections are integral therewith.

What is claimed is:

l. A filter leaf assembly comprising a relatively thin circular leaf member of a plastic material having sufficient thickness to be structurally self-supporting and having opposed faces, a plurality of cylindrical projections relatively closely spaced in a regular pattern on each face, said projections being of a uniform height and integral with the respective faces, a peripheral rib on each face of said leaf member being of a height equal to said projections, a circumferential groove in the outer peripheral edge of said leaf member, caulking means in said circumferential groove, and filter media on each of said leaf faces and positioned on the ends of said projections and said ribs by said caulking means and by a generally U-shaped molded binding composed of two halves clamped around the peripheral edges of said filter media relative to said leaf assembly, said leaf member having a central opening with a hub positioned therein, said hub having an external flange on one end of said hub, and means for retaining said leaf member on said hub against said flange, annular grooves in the outer peripheral surface of said hub communicating with said spaced projections on both faces of said leaf members, and

passage means in said hub extending from said annular grooves to the interior of said hub.

2. A filter leaf assembly as claimed in claim 1 with said leaf member being rectangular and wherein said opening is in one edge thereof, and hose connection means attached to said edge to communicate with the cylindrical projections on both faces of the leaf member.

3. A filter leaf assembly as claimed in claim 1 wherein the leaf member is of foamed plastic. 

2. A filter leaf assembly as claimed in claim 1 with said leaf member being rectangular and wherein said opening is in one edge thereof, and hose connection means attached to said edge to communicate with the cylindrical projections on both faces of the leaf member.
 3. A filter leaf assembly as claimed in claim 1 wherein the leaf member is of foamed plastic. 